Athens, University of Georgia. pp. 564–573 (1986), McKenzie M. E. & Long P. L. Poultry Science 65, 892–897 (1986)) or recombinant Eimeria polypeptides (Danforth H. D., Augustine P. C., Ruff M. D., McCandliss R., Strausberg R. L. & Likel M. Poultry Science 68, 1643–1652 (1989), Jenkins M. C., Augustine P. C., Danforth H. D. & Barta J. R. Infection and Immunity 59, 4042–4048 (1991)) only limited protection against challenge infection could be achieved. The parasite stages responsible for the induction of protective immunity are generally thought to be early asexual developmental stages (Jenkins et al. 1991). Initially, selection of candidate antigens was performed using antibodies from immune chickens but, in view of the fundamental role of cell mediated responses in protective immunity (reviewed in Lillehoj H. S. & Trout J. M. Avian Pathology 22, 3–31 (1993), Rose M. E. In: Poultry Immunology (Ed.: T. F. Davison, T. R. Morris and L. N. Payne), Carfax Publishing Company, Oxfordshire, U. K. pp. 265–299 (1996), attention has now focused, next to B-cell inducing antigens, on screening antigens for their ability to stimulate specific T-cell responses (Dunn P. P. J., Billington K., Bumstead J. M. & Tomley F. M. Molecular and Biochemical Parasitology 70, 211–215 (1995)).
It is an objective of the present invention to provide polypeptides that are capable of inducing protection against the pathogenic effects of Eimeria infection in poultry.